EXPERIMENT STATION REPORT. 591 



combination, but if not, add more water to the extent of a gallon, 

 and there may even be an excess. An excess is indicated when the 

 material changes to an opaque, creamy tint instead of remaining 

 .a clear brown liquid, but the excess will not affect the material so 

 as to prevent use or lessen effect. An imporlant recommendation 

 is that the ''Scalecide" should be poured into the water instead of 

 'water into "Scalecide." If the oil is put in first and water is 

 added, there will l)e adhesion to the sides of the vessel and the 

 formation of masses which disintegrate slowly. If the oil is poured 

 into the water it mixes readily. It does not matter how cold the 

 water is, although it does not dissolve as readily at thirty-two de- 

 crees to thirty-five degrees as at fifty degrees to sixty degrees, but 

 hot water should not be used. Cold does not affect the combina- 

 tion, but heat may do so by causing the loss of water in the emul- 

 sion, hence do not store where the temperature gets above seventy 

 degrees if it can be avoided. Mr. Pratt assures me that their offer 

 to replace unsatisfactory material is made in good faith, but they 

 cannot, of course, undertake to guarantee effect where so much 

 depends upon the user. They assume liability only for defects in 

 the material due to their neglect or failure, and it is to bring out 

 j)ossible defects in their methods that they retain samples from 

 ■each lot sent out. 



After going through the factory and watching the process of mak- 

 ing up a carload, and examining the methods of checking, filling 

 and shipping, it seems almost impossible that there should be any 

 material difference in the product sent out, or in the percentage of 

 actual petroleum oil in the different lots. Differences in results 

 must be due to factors outside of the composition of the material 

 itself; but for his own protectioji and to make certain of the best 

 ■conditions as to material, every purchaser is advised to use the 

 following precautions : 



On receiving a lot of '^Scalecide," make a note of the number 

 •of the emulsion or lot on each barrel or can. Always shake or 

 mix up well before opening. Test by taking up a spoonful and 

 allowing it to drop slowly into a glass of water; if it dissolves 

 readily and completely and forms a milky emulsion, it is in con- 

 dition for use. If there is trouble in dissolving, notify the maker 

 if it is a fresh lot; add a little water if it is old. Always put the 

 water, or at least a large part of it, into the spray tank first and 

 pour the "Scalecide" into the water slowly. The resulting emul- 



